1,720,988 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Exploring Sustainable Alternatives to OPC: Incorporation of Recycled Ceramics into Limestone Calcined Clay Cement
No full textLow-carbon binders, particularly Limestone Calcined Clay Cement (LC3), are emerging as sustainable alternatives to Ordinary Portland Cement (OPC). LC3 significantly reduces CO2 emissions, offering satisfying mechanical strength, increased durability, and reduced environmental impact. Simultaneously, the traditional ceramic production process generates residual powder that could serve as a viable cement substitute. Ceramic waste materials, including scraps, waste powder, sludge, and tile residues, may exhibit pozzolanic behaviour, making them valuable in construction materials.
This research investigates potential benefits and challenges of incorporating grinding powders of porcelain stoneware into low-carbon cement. The LC3 formulated with recycled ceramic was analysed and compared to reference cement containing 50% of clinker and calcined clay to limestone proportion of 2:1. Mortar rheology was investigated by flow table test at different superplasticizer dosage and the fresh material was further investigated by 1H Time Domain-Nuclear Magnetic Resonance (TD-NMR) to detect the amount of capillary water available to fluidify the mixture. Colorimetric analysis was performed to quantify the visual impact of ceramic substituents on the material. Mechanical strength at 2 days enabled to validate the suitability of industrial waste to prepare eco-friendly mortar.
The results show that the particle size distribution plays a crucial role in regulating superplasticizer need to reach acceptable workability. The TD-NMR findings validated that the cement composition influences the amount of detectable capillary water. However, the assessment of mechanical strength highlighted that ceramic waste can provides comparable performance to reference material encouraging the possible integration of recycled ceramics into low-carbon cement
Force measurements by AFM on clinker surfaces and model systems in aqueous solutions containing superplasticizer
No full textRheological control of cementitious composites incorporating ceramic wastes for 3D printing applications
Full text linkIn response to the environmental impact of cement production and industrial discarded materials, this study
explores the valorisation of ceramic wastes as replacement of clinker in low-carbon cementitious composites for
application in additive manufacturing. Ceramic wastes from different sources were used as substitute of calcined
clay in limestone calcined clay cement (LC3) mortar. The embodied CO2 reduction of these new binders exceeds
40 % compared to Portland Cement (PC), thus representing a notable advancement in low-emission cementitious
composites. The influence of six ceramic wastes on the fresh state performance of mortar was assessed through
flow table tests and rheological measurements. A ball measuring system was used to assess viscosity, static yield
stress, and their early-age evolution, combining the high resolution of benchtop rheometers with the possibility
of testing of 3D-printable mortars with aggregates up to 2 mm, featuring high yield stress values. Numerical
simulations based on the Particle Finite Element Method were then used to evaluate the printability of developed
mix designs, avoiding time consuming trial and error testing campaigns and paving the way for through printing
trials on a selected set of waste materials.
Numerical simulations highlighted that, while all tested formulations showed good performance for small-
scale 3D printing, careful material selection becomes crucial when targeting larger structures to ensure stabil-
ity and minimize deformation. Additionally, the simulations allowed prediction of material behaviour, partic-
ularly valuable given the high variability of waste-based constituents, emphasizing the innovative combination
of circular economy concepts with a unique approach to additive manufacturing supported by numerical
simulations
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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